Recently industry analysts have coined to the term Water-Energy Nexus to describe the important relationship between energy and water. Just about every method of producing energy requires a surprising amount of fresh water. Likewise, our modern water infrastructure requires a great deal of energy to maintain. Global shortages in both energy and water mean that the problems must be addressed with common solutions.
Few places in the world feel the water-energy nexus more than Texas. Texas has been dealing with well publicized difficulties with electricity capacity. State officials worry that the capacity of the Texas electricity grid will not be able to keep up with growing demand. At the same time, population growth and recent drought have put a strain on the Texas water supply.
Natural gas and coal are the primary fuels used to produce Texas electricity. Both of these types of energy require large amounts of water. Fresh water is required to extract the materials from the ground; particularly in the case of natural gas. Hydraulic fracturing, or “fracking”, requires that large amounts of water be pumped into the ground to free trapped natural gas.
Both types of energy also require large amounts of water for the power plants that burn them to create electricity. Fresh water must continually be pumped in to cool the equipment used to convert the fuel to electricity. This has created a situation where producers of electricity are sometimes competing with agricultural or municipal users of water for limited fresh water resources. In recent years, the water-permitting process has sometimes lead to problems getting new electricity generating projects underway.
Wind energy and solar energy are among the least water intensive energy sources. However, these sources are not economically competitive with cheaper sources like natural gas. Texas has one of the biggest wind energy sectors in the world. The industry has been nurtured by tax credits, state level renewable energy mandates and an abundance of wind in west Texas. Despite this, however, wind is still a minority contributor to the state’s electricity portfolio and will continue to be so for the foreseeable future.
One recent report proposes a switch from coal to natural gas for Texas electricity as a more water friendly approach to the state’s electricity needs. Although both types of energy are relatively thirsty compared to wind or solar, natural gas tends to require less water per unit of electricity even when fracking is taken into account.
According to the report by researchers at the University of Texas at Austin, “Replacing Texas’ coal-fired power plants with natural gas combined cycle plants (NGCCs) would reduce annual freshwater consumption in the state by an estimated 53 billion gallons per year, or 60% of Texas coal power’s water footprint, largely due to the higher efficiency of NGCCs,”
Natural gas is already the largest source of electric power for the state. As a power to choose state, Texas electricity is driven largely by market dynamics. The recent low electricity rates in Texas are largely due to cheap natural gas. Natural gas is already positioned to gain more ground in the state because it is cheaper than coal and doesn’t carry the additional regulatory burden of coal. The newest report adds an yet another argument for natural gas going forward.
- More water is used globally in the production of energy than for irrigation.
- Per power plant, nuclear energy consumes the most water.
- 190 billion gallons of fresh water per day is withdrawn from U.S. water sources to support electricity production.
- 85% of the growth in U.S. water demand over the next 20 years is expected to come from the energy sector.